Hair straightener



FIG. 1 is a front, left and top perspective view of a hair straightener, showing my design.

FIG. 2 is a rear, right and bottom perspective view thereof.

FIG. 3 is a front elevation view thereof.

FIG. 4 is a rear elevation view thereof.

FIG. 5 is a left side elevation view thereof.

FIG. 6 is a right side elevation view thereof.

FIG. 7 is a top plan view thereof.

FIG. 8 is a bottom plan view thereof; and,

FIG. 9 is another front, left and top perspective view of the hair straightener in an open state.

The broken lines depict portions of the hair straightener that form no part of the claimed design. 

CLAIM The ornamental design for a hair straightener, as shown and described. 